Air-conditioning apparatus

ABSTRACT

An air-conditioning apparatus includes an outdoor unit including an outdoor heat exchanger; an indoor unit including an indoor heat exchanger; and a relay unit provided between the outdoor unit and the indoor unit and including one or more first refrigerant supply pipes and one or more second refrigerant supply pipes that are connected to the indoor heat exchanger of the indoor unit. The one or more first refrigerant supply pipes and the one or more second refrigerant supply pipes protrude from the same side surface of the relay unit. The one or more first refrigerant supply pipes are each provided above an associated one of the one or more second refrigerant supply pipes. Part of the one or more first refrigerant supply pipes that protrudes from the side surface is longer than part of the one or more second refrigerant supply pipes that protrudes from the side surface.

CROSS REFERENCE TO RELATED APPLICATION

This application is a U.S. national stage application of InternationalPatent Application No. PCT/JP2019/019539 filed on May 16, 2019, thedisclosure of which is incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to an air-conditioning apparatusincluding a relay unit installed between an outdoor unit and an indoorunit.

BACKGROUND

In an air-conditioning apparatus, refrigerant that carries heat iscirculated through pipes that connects an outdoor unit and an indoorunit, to thereby generate conditioned air.

Recently, air-conditioning apparatuses capable of simultaneouslyperforming cooling and heating have been developed. In such a kind of anair-conditioning apparatus, a plurality of indoor units are installed,and a relay unit is thus installed between an outdoor unit and theindoor units. The relay unit distributes refrigerant to the indoorunits.

For example, an air-conditioning apparatus disclosed in PatentLiterature 1 is an existing air-conditioning apparatus capable ofsimultaneously performing cooling and heating. The air-conditioningapparatus of Patent Literature 1 includes a heat source unit thatoperates as an outdoor unit, a plurality of indoor units, and a relayunit that is installed between the heat source unit and the indoorunits. The relay unit of the air-conditioning apparatus has a pluralityof branch ports that allow the relay unit to be connected to therespective indoor units.

In such a kind of air-conditioning apparatus, in general, the branchports of the relay unit are connected using flare nuts to pipes that areinstalled at an actual place and connected to the indoor units. Each ofthe branch ports of the relay unit is formed such that a joint is brazedto a copper pipe. Each of the pipes at the actual place includes a flarenut provided at one end of each pipe. The flare nut of the pipe at theactual place is screwed onto the joint of the branch port using aspanner, whereby the pipe at the actual place is connected to the branchport of the relay unit.

PATENT LITERATURE

Patent Literature 1: Japanese Patent No. 3235189

In such an existing air-conditioning apparatus as described above, in aconnection work of connecting the pipes at the actual place to thebranch ports of the relay unit, each of the flare nuts is tightenedwhile a hexagonal portion of an associated one of the joints is beingfastened with a spanner. However, since liquid pipes and gas pipes areinstalled as the pipes at the actual place, the relay unit are formed tohave a plurality of branch ports for the pipes at the actual place.Thus, the distance between any adjacent two of the branch ports in therelay unit is short. Therefore, in such a connection work as describedabove, when a pipe at the actual place is connected to an associatedbranch port of the relay unit, this connection may be obstructed byanother branch port. If so, a spanner cannot be engaged with thehexagonal portion of the joint at an appropriate angle. In such a case,if the spanner is forcedly moved in such a manner as to apply a force tothe hexagonal portion of the joint, the spanner may be slipped, thusdeforming the joint. Consequently, a crack may be formed at the brazedportion of the joint, causing a leak of refrigerant.

SUMMARY

The present disclosure is applied to solve the above problem, andrelates to an air-conditioning apparatus that enables the workability ofa connection work of connecting a relay unit to pipes connected to anindoor unit to be improved.

An air-conditioning apparatus according to an embodiment of the presentdisclosure includes An air-conditioning apparatus includes an outdoorunit including an outdoor heat exchanger; an indoor unit including anindoor heat exchanger; and a relay unit provided between the outdoorunit and the indoor unit and including one or more first refrigerantsupply pipes and one or more second refrigerant supply pipes that areconnected to the indoor heat exchanger of the indoor unit. The one ormore first refrigerant supply pipes and the one or more secondrefrigerant supply pipes protrude from the same side surface of therelay unit. The one or more first refrigerant supply pipes are eachprovided above an associated one of the one or more second refrigerantsupply pipes. Part of the one or more first refrigerant supply pipesthat protrudes from the side surface is longer than part of the one ormore second refrigerant supply pipes that protrudes from the sidesurface.

In the air-conditioning apparatus according to the embodiment of thepresent disclosure, it is possible to improve the workability of aconnection work of connecting the relay unit to pipes connected to theindoor unit.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram illustrating a configuration of an air-conditioningapparatus according to Embodiment 1.

FIG. 2 is a perspective view of the entire configuration of a relay unitincluded in the air-conditioning apparatus according to Embodiment 1.

FIG. 3 is a partial side view illustrating a configuration of each ofrefrigerant supply pipes of the relay unit in Embodiment 1.

FIG. 4 is a partial side view of the configuration of another example ofthe refrigerant supply pipe of the relay unit in Embodiment 1.

FIG. 5 is a diagram illustrating a spanner engaged with a joint includedin the refrigerant supply pipe as illustrated in FIG. 4.

FIG. 6 is a partial side view illustrating a configuration of each ofrefrigerant supply pipes of a relay unit of a reference example.

FIG. 7 is a partial side view illustrating a configuration of a jointincluded in the refrigerant supply pipe of the relay unit of thereference example.

FIG. 8 is a diagram illustrating the joint included in the refrigerantsupply pipe of the relay unit of the reference example in the case wherethe joint is deformed.

FIG. 9 is a diagram illustrating the spanner engaged with the joint inthe reference example as illustrated in FIG. 7.

DESCRIPTION OF EMBODIMENTS

An embodiment of an air-conditioning apparatus according to the presentdisclosure will be described with reference to the drawings.

Embodiment 1

An air-conditioning apparatus according to Embodiment 1 includes aplurality of indoor units and is capable of performing a cooling onlyoperation, a heating only operation, and a simultaneous cooling andheating operation. FIG. 1 illustrates a configuration of anair-conditioning apparatus 100 according to Embodiment 1. Theair-conditioning apparatus 100 includes an outdoor unit 51, indoor units52 a and 52 b, and a relay unit 53. The relay unit 53 is installedbetween the outdoor unit 51 and the indoor units 52 a and 52 b.

The outdoor unit 51 and the relay unit 53 are connected by a firstliquid pipe 104 through which liquid refrigerant flows and a first gaspipe 103 through which gas refrigerant flows.

The relay unit 53 and the indoor unit 52 a are connected by a secondliquid pipe 105 a through which the liquid refrigerant flows and asecond gas pipe 106 a through which the gas refrigerant flows.Similarly, the relay unit 53 and the indoor unit 52 b are connected by asecond liquid pipe 105 b through which the liquid refrigerant flows anda second gas pipe 106 b through which the gas refrigerant flows.

Although the air-conditioning apparatus 100 according to Embodiment 1 isan air-conditioning apparatus in which the indoor units 52 a and 52 bcan perform a cooling operation or a heating operation independently ofeach other, Embodiment 1 is not limited to this example. In other words,Embodiment 1 is applicable to any type of air-conditioning apparatus aslong as the air-conditioning apparatus includes the relay unit 53.

Components included in the air-conditioning apparatus 100 will bedescribed.

[Outdoor Unit 51]

The outdoor unit 51 includes a compressor 1, a four-way valve 3, anoutdoor heat exchanger 2, an accumulator 4, a refrigerant flow controlunit 54, and an outdoor-side control unit 201. The compressor 1 sucks,compresses, and discharges refrigerant. As the compressor 1, a devicewhose capacity is controlled to change the amount of refrigerant to besent per unit time, such as an inverter circuit, can be used. On adischarge side of the compressor 1, a first pressure sensor 31 isprovided, and on a suction side of the compressor 1, a second pressuresensor 32 is provided. The first pressure sensor 31 detects a pressurePd of discharged refrigerant. The second pressure sensor 32 detects apressure Ps of refrigerant to be sucked into the compressor 1. Thepressure Pd detected by the first pressure sensor 31 and the pressure Psdetected by the second pressure sensor 32 are transmitted as data to theoutdoor-side control unit 201. The outdoor-side control unit 201operates as a controller that performs a centralized control of theentire air-conditioning apparatus.

The outdoor heat exchanger 2 causes refrigerant to flow therein andcauses heat exchange to be performed between the refrigerant and outdoorair. In the heating operation, the outdoor heat exchanger 2 operates asan evaporator to evaporate and gasify the refrigerant. In the coolingoperation, the outdoor heat exchanger 2 operates as a condenser tocondense and liquefy the refrigerant. The four-way valve 3 is a valvethat switches the flow of the refrigerant between flows of therefrigerant for respective operations. That is, when the four-way valve3 switches the flow of the refrigerant, the operation is switchedbetween, for example, the cooling operation and the heating operation.The accumulator 4 accumulates an excess of liquid refrigerant. Therefrigerant flow control unit 54 includes check valves 7 a, 7 b, 7 c,and 7 d, which will be described later, and each of which permits therefrigerant to flow only in one direction.

[Refrigerant Flow Control Unit 54]

The refrigerant flow control unit 54 includes four connection pipes 130,131, 132, and 133 that connect connection points a, b, c, and d and thefour check valves 7 a, 7 b, 7 c, and 7 d each of which permits therefrigerant to flow in one direction. The refrigerant flow control unit54 is one of the components of the outdoor unit 51. The connection pipe130 is a pipe that connects the connection point c and the connectionpoint a. The connection pipe 131 is a pipe that connects the connectionpoint d and the connection point b. The connection pipe 132 is a pipethat connects the connection point c and the connection point d. Theconnection pipe 133 is a pipe that connects the connection point a andthe connection point b. Furthermore, the connection pipe 132 connectsthe first gas pipe 103 connected to the relay unit 53 and a third gaspipe 102 connected to the compressor 1. In addition, the connection pipe133 connects the first liquid pipe 104 connected to the relay unit 53and a third liquid pipe 101 connected to the compressor 1.

The check valve 7 a is provided at the connection pipe 132 and permitsthe refrigerant to flow in a direction from the connection point ctoward the connection point d. The check valve 7 b is provided at theconnection pipe 133 and permits the refrigerant to flow in a directionfrom the connection point a toward the connection point b. The checkvalve 7 c is provided at the connection pipe 131 and permits therefrigerant to flow in a direction from the connection point d towardthe connection point b. The check valve 7 d is provided at theconnection pipe 130 and permits the refrigerant to flow in a directionfrom the connection point c toward the connection point a.

[Indoor Units 52 a and 52 b]

The indoor unit 52 a includes an indoor heat exchanger 5 a, an indoorexpansion device 6 a, and an indoor-side control unit 202 a. The indoorunit 52 b includes an indoor heat exchanger 5 b, an indoor expansiondevice 6 b, and an indoor-side control unit 202 b. The second gas pipe106 a is connected to one end of the indoor heat exchanger 5 a. Thesecond gas pipe 106 b is connected to one end of the indoor heatexchanger 5 b. The indoor heat exchangers 5 a and 5 b each causerefrigerant that has passed through the relay unit 53 to flow therein,and cause heat exchange to be performed between the refrigerant and airto be conditioned. In the heating operation, the indoor heat exchangers5 a and 5 b each operate as a condenser to condense and liquefy therefrigerant. In the cooling operation, the indoor heat exchangers 5 aand 5 b each operate as an evaporator to evaporate and gasify therefrigerant. The other end of the indoor heat exchanger 5 a is connectedto the indoor expansion device 6 a. The other end of the indoor heatexchanger 5 b is connected to the indoor expansion device 6 b. Theindoor expansion device 6 a is connected to the second liquid pipe 105a. The indoor expansion device 6 b is connected to the second liquidpipe 105 b. The indoor expansion devices 6 a and 6 b each operate as apressure reducing valve and an expansion valve to reduce the pressure ofthe refrigerant and expand the refrigerant. Each of the indoor expansiondevices 6 a and 6 b is only required to be capable of adjusting thepressure of the refrigerant, depending on an air-conditioning load. Forexample, as each of the indoor expansion devices 6 a and 6 b, a flowcontrol device, such as an electronic expansion valve, can be used. Inthe indoor unit 52 a, a first temperature sensor 33 a and a secondtemperature sensor 34 a are provided. In the indoor unit 52 b, a firsttemperature sensor 33 b and a second temperature sensor 34 b areprovided. The first temperature sensor 33 a and the second temperaturesensor 34 a each detect the temperature of the refrigerant that flowsinto or out of the indoor heat exchanger 5 a. The first temperaturesensor 33 b and the second temperature sensor 34 b each detect thetemperature of the refrigerant that flows into or out of the indoor heatexchanger 5 b. The first temperature sensor 33 a and the secondtemperature sensor 34 a each transmit a signal indicating the detectedtemperature to the indoor-side control unit 202 a. Furthermore, thefirst temperature sensor 33 b and the second temperature sensor 34 beach transmit a signal indicating the detected temperature to theindoor-side control unit 202 b.

[Relay Unit 53]

The relay unit 53 includes a gas-liquid separator 8, first on-off valves9 a and 9 b, second on-off valves 10 a and 10 b, a first expansiondevice 11, a second expansion device 12, a first heat exchanger 13, asecond heat exchanger 14, check valves 15 a, 15 b, 16 a, and 16 b, and arelay-unit control unit 203. The components of the relay unit 53 arecontrolled by the relay-unit control unit 203. Furthermore, thecomponents of the relay unit 53 are connected by a first bypass pipe110, a first relay-unit liquid pipe 111, a first relay-unit gas pipe112, and a second bypass pipe 113. The relay unit 53 is connected to theoutdoor unit 51 by the first liquid pipe 104 and the first gas pipe 103.Furthermore, the relay unit 53 is connected to the indoor unit 52 a bythe second liquid pipe 105 a and the second gas pipe 106 a, and isconnected to the indoor unit 52 b by the second liquid pipe 105 b andthe second gas pipe 106 b. The relay unit 53 controls the flow of therefrigerant between the outdoor unit 51 and each of the indoor units 52a and 52 b. The indoor units 52 a and 52 b perform the simultaneouscooling and heating operation. The term “simultaneous cooling andheating operation” means an operation in which one of the indoor unitsperforms the cooling operation and the other performs the heatingoperation. Although FIG. 1 illustrates the two indoor units, the relayunit 53 can be connected to up to 16 indoor units 52 by increasing thenumber of on-off valves 9, that of on-off valves 10, that of checkvalves 15, and that of check valves 16. Also, although it is describedby way of example that the maximum number of indoor units 52 that can beprovided is 16, it is not limiting, and the maximum number of indoorunits 52 may be any number larger than or equal to 1.

The gas-liquid separator 8 separates the refrigerant into liquidrefrigerant and gas refrigerant, and is connected to the first liquidpipe 104, the first relay-unit liquid pipe 111, and the first relay-unitgas pipe 112. The first liquid pipe 104 connects the outdoor unit 51 andthe gas-liquid separator 8. The first relay-unit liquid pipe 111connects the gas-liquid separator 8 and each of the check valves 15 aand 15 b. The first relay-unit gas pipe 112 connects the gas-liquidseparator 8 and each of the first on-off valves 9 a and 9 b.

The second gas pipe 106 a branches and connects to the first on-offvalve 9 a and the second on-off valve 10 a. Similarly, the second gaspipe 106 b branches and connects to the first on-off valve 9 b and thesecond on-off valve 10 b. Each of the first on-off valves 9 a and 9 b isopened to permit the gas refrigerant that flows through the firstrelay-unit gas pipe 112 to flow out of the relay unit 53, or is closedto shut out the flow of the gas refrigerant. Each of the first on-offvalves 9 a and 9 b is in the opened state while the indoor unit 52 a or52 b connected to the valve by the second gas pipe 106 a or 106 b is inthe heating operation. Each of the second on-off valves 10 a and 10 b isopened to permit gas refrigerant that flows from the second gas pipe 106a or 106 b of the indoor unit 52 a or 52 b to flows into the relay unit53, or is closed to shut out the flow of the gas refrigerant. Each ofthe second on-off valves 10 a and 10 b is in the opened state while theindoor unit 52 a or 52 b connected to the valve by the second gas pipe106 a or 106 b is in the cooling operation. The second on-off valves 10a and 10 b are connected to the first gas pipe 103.

The first heat exchanger 13 causes the liquid refrigerant separated bythe gas-liquid separator 8 and liquid refrigerant that has passedthrough the second heat exchanger 14 to flow in the first heat exchanger13, and cause heat exchange to be performed between the liquidrefrigerants that flow in the first heat exchanger 13. The firstexpansion device 11 reduces the pressure of the liquid refrigerant thathas passed through the first heat exchanger 13 and causes therefrigerant to flow into the second heat exchanger 14. The second heatexchanger 14 causes the refrigerant that has been reduced in pressure bythe first expansion device 11 and liquid refrigerant that has beenreduced in pressure by the second expansion device 12 to flow in thesecond heat exchanger 14, and cause heat exchange to be performedbetween the refrigerant and the liquid refrigerant that flow in thesecond heat exchanger 14. The first heat exchanger 13, the firstexpansion device 11, and the second heat exchanger 14 are interposedbetween the gas-liquid separator 8 and a relay-unit trifurcate portion55, and are connected by the first relay-unit liquid pipe 111. The firstbypass pipe 110 connects the relay-unit trifurcate portion 55 and thefirst gas pipe 103 via the second expansion device 12, the second heatexchanger 14, and the first heat exchanger 13. The first bypass pipe 110collects liquid refrigerant and returns the liquid refrigerant to theoutdoor unit 51. As the first expansion device 11 and the secondexpansion device 12, a flow control device whose opening degree can bechanged to finely control the flow rate, such as an electronic expansionvalve, may be used.

The check valve 16 a permits the refrigerant to flow in a direction fromthe connection point f to the connection point e. The check valve 15 apermits the refrigerant to flow in a direction from the connection pointg to the connection point f. The check valve 16 b permits therefrigerant to flow in a direction from the connection point h to theconnection point e. The check valve 15 b permits the refrigerant to flowin a direction from the connection point g to the connection point h.The first relay-unit liquid pipe 111 branches at the connection point gand connects to the check valves 15 a and 15 b. The second liquid pipe105 a branches at the connection point f and connects to the checkvalves 15 a and 16 a. The check valves 15 a and 16 a are connected tothe second liquid pipe 105 a such that refrigerant from the check valve15 a flows to the second liquid pipe 105 a and refrigerant from thesecond liquid pipe 105 a flows to the check valve 16 a. Similarly, thesecond liquid pipe 105 b branches at the connection point h and connectsto the check valves 15 b and 16 b. The check valves 15 b and 16 b areconnected to the second liquid pipe 105 b such that refrigerant from thecheck valve 15 b flows to the second liquid pipe 105 b and refrigerantfrom the second liquid pipe 105 b flows to the check valve 16 b. Thesecond bypass pipe 113 connects the first heat exchanger 13 and each ofthe check valves 16 a and 16 b. The second bypass pipe 113 branches atthe connection point e and connects to the check valves 16 a and 16 b.The connection point g is connected to the first bypass pipe 110 and thefirst relay-unit liquid pipe 111 via the relay-unit trifurcate portion55.

The configuration of the relay unit 53 in Embodiment 1 will be describedwith reference to FIG. 2. FIG. 2 is a perspective view of the entireconfiguration of the relay unit included in the air-conditioningapparatus according to Embodiment 1. FIG. 2 illustrates an appearance ofthe relay unit 53 that can be connected to up to 16 indoor units 52. Asillustrated in FIG. 2, the relay unit 53 is formed in the shape of acuboid. In other words, the relay unit 53 has an upper surface, a lowersurface, and four side surfaces. Of the four side surfaces of the relayunit 53, one of two side surfaces that extend in a width direction willbe referred to as “side surface A”, and one of two side surfaces thatextend in a longitudinal direction will be referred to as “side surfaceB”. As illustrated in FIG. 2, the side surface A and the side surface Bare adjacent to each other and perpendicular to each other.

As illustrated in FIG. 2, at the side surface A, a second relay-unit gaspipe 141 and a second relay-unit liquid pipe 142 are provided. Thesecond relay-unit gas pipe 141 and the second relay-unit liquid pipe 142protrude outwardly from the side surface A in a direction perpendicularto the side surface A. The second relay-unit gas pipe 141 is joined bybrazing to the first gas pipe 103 that extends as illustrated in FIG. 1.The second relay-unit liquid pipe 142 is joined by brazing to the firstliquid pipe 104 (see FIG. 1).

As illustrated in FIG. 2, at the side surface B, 16 liquid-refrigerantsupply pipes 143 and 16 gas-refrigerant supply pipes 144 are provided.The liquid-refrigerant supply pipes 143 and the gas-refrigerant supplypipes 144 protrude outwardly from the side surface B in a directionperpendicular to the side surface B. Each of the liquid-refrigerantsupply pipes 143 is a first refrigerant supply pipe. Each of thegas-refrigerant supply pipes 144 is a second refrigerant supply pipe. Tobe more specific, a single first refrigerant supply pipe and a singlesecond refrigerant supply pipe are provided as a single pair ofrefrigerant supply pipes. The single pair of refrigerant supply pipesare connected to a single indoor unit 52. FIG. 2 illustrates 16 pairs ofrefrigerant supply pipes, that is, 16 pairs of liquid-refrigerant supplypipes 143 and gas-refrigerant supply pipes 144. Thus, the relay unit 53can be connected to up to 16 indoor units 52. However, as describedabove, each of the number of liquid-refrigerant supply pipes 143 and thenumber of gas-refrigerant supply pipes 144 is not limited to 16 and maybe any number as long as it is larger than or equal to the number ofindoor units 52 to which the relay unit is connected. Theliquid-refrigerant supply pipes 143 are connected by flare nuts to thesecond liquid pipes 105 a and 105 b that extend as illustrated inFIG. 1. Furthermore, the gas-refrigerant supply pipes 144 are connectedby flare nuts to the second gas pipes 106 a and 106 b that extend asillustrated in FIG. 1. The liquid-refrigerant supply pipes 143 arelocated above the gas-refrigerant supply pipes 144. Each of theliquid-refrigerant supply pipes 143 may be offset rightwards orleftwards from an associated one of the gas-refrigerant supply pipes 144only by a predetermined distance, not directly above the associatedgas-refrigerant supply pipe 144. The relay unit 53 further includes ahanging lug 145. When installed, the relay unit 53 is hung with thehanging lug 145, using, for example, hanging bolts in a space above aceiling in a building, for example. Hereinafter, a direction in whichthe liquid-refrigerant supply pipes 143 and the gas-refrigerant supplypipes 144 extend, or the direction perpendicular to the side surface B,will be referred to as “axial direction” of the liquid-refrigerantsupply pipes 143 and the gas-refrigerant supply pipes 144. Therefore,the axial direction is a horizontal direction when the relay unit 53 ishung.

In the case where the two indoor units 52 a and 52 b are installed, asdescribed above, two liquid-refrigerant supply pipes 143 are connectedto respective second liquid pipes, that is, the second liquid pipes 105a and 105 b, and two gas-refrigerant supply pipes 144 are connected torespective gas pipes, that is, the second gas pipes 106 a and 106 b.However, in order that the above configuration be simply described, thefollowing description is made with respect to an example in which asingle liquid-refrigerant supply pipe 143 is connected to the secondliquid pipe 105 a, and a single gas-refrigerant supply pipe 144 isconnected to the second gas pipe 106 a. That is, a descriptionconcerning the second liquid pipe 105 b and the second gas pipe 106 bwill be omitted. FIGS. 6 to 9 illustrate a relay unit 53R as a referenceexample to be referred to in an explanation of advantages ofEmbodiment 1. Similarly, a description concerning the configuration asillustrated in FIGS. 6 to 9 will also be simplified and made withrespect to an example in which a liquid-refrigerant supply pipe 143R isconnected to the second liquid pipe 105 a, and a gas-refrigerant supplypipe 144R is connected to the second gas pipe 106 a. That is, regardingthe configuration as illustrated in each of FIGS. 6 to 9, a descriptionconcerning the second liquid pipe 105 b and the second gas pipe 106 bwill be omitted.

FIG. 6 is a partial side view illustrating the configuration of each ofthe refrigerant supply pipes of the relay unit of the reference example.FIG. 6 is a side view of the relay unit 53R of the reference example asviewed side-on with respect to the side surface A. As illustrated inFIG. 6, the liquid-refrigerant supply pipe 143R and the gas-refrigerantsupply pipe 144R protrude from the side surface B. Theliquid-refrigerant supply pipe 143R is provided above thegas-refrigerant supply pipe 144R. The length L1 of a protruding portionof the liquid-refrigerant supply pipe 143R is less than or equal to thelength L2 of that of the gas-refrigerant supply pipe 144R. Theliquid-refrigerant supply pipe 143R includes a first pipe 161 aR fixedto the side surface B of the relay unit 53R and a liquid-pipe joint 151aR located at a distal end of the first pipe 161 aR. The liquid-pipejoint 151 aR is a first joint. The liquid-pipe joint 151 aR is connectedto the second liquid pipe 105 a using a liquid-pipe flare nut 152 aR.The liquid-pipe flare nut 152 aR is provided at a distal end of thesecond liquid pipe 105 a. The gas-refrigerant supply pipe 144R includesa second pipe 161 bR fixed to the side surface B of the relay unit 53Rand a gas-pipe joint 151 bR jointed at a distal end of the second pipe161 bR. The gas-pipe joint 151 bR is a second joint. The gas-pipe joint151 bR is connected to the second gas pipe 106 a using a gas-pipe flarenut 152 bR. The gas-pipe flare nut 152 bR is provided at a distal end ofthe second gas pipe 106 a.

FIG. 7 is a partial side view illustrating a configuration of the jointprovided in the refrigerant supply pipe of the relay unit in thereference example. FIG. 7 illustrates a configuration of the liquid-pipejoint 151 aR of the reference example as illustrated in FIG. 6. Asillustrated in FIG. 7, the liquid-pipe joint 151 aR includes a firstportion 155R that is a hexagonal pipe and a second portion 156R to befitted in the liquid-pipe flare nut 152 aR. Since the first portion 155Ris the hexagonal pipe, the first portion 155R has six outer sidesurfaces and six outer corners. An end of the first portion 155R in theaxial direction is brazed and fixed to the first pipe 161 aR of theliquid-refrigerant supply pipe 143R. This brazed portion willhereinafter be referred to as “brazed portion 154R”. The outsidediameter of the first portion 155R is larger than that of the secondportion 156R. The second portion 156R is formed in the shape of acircular tube, and a distal end portion of the second portion 156R istapered toward a distal end of the distal end portion.

Connection of the liquid-refrigerant supply pipe 143R of the relay unit53R to the second liquid pipe 105 a using the liquid-pipe flare nut 152aR will be described. Since the relay unit 53R is hung in a space abovea ceiling, a spanner is engaged with the liquid-pipe joint 151 aR frombelow the relay unit 53R to fasten the liquid-pipe joint 151 aR, and theliquid-pipe flare nut 152 aR is tightened using a torque wrench. Thus,the gas-refrigerant supply pipe 144R located below theliquid-refrigerant supply pipe 143R is an obstruction to a work ofengaging the spanner with the liquid-pipe joint 151 aR. That is, it ishard to engage the spanner with the liquid-pipe joint 151 aR. In view ofthis point, the spanner is diagonally moved and engaged with the firstportion 155R of the liquid-pipe joint 151 aR, or is moved from above andengaged with the first portion 155R. In either case, the spanner islocated to hold the first portion 155R of the liquid-pipe joint 151 aRat an inappropriate angle. FIGS. 8 and 9 illustrate a state in which thespanner is located to hold the first portion 155R. FIG. 8 is a diagramillustrating the joint included in the liquid-refrigerant supply pipe ofthe relay unit 53R of the reference example in the case where the jointis deformed. FIG. 9 is a diagram illustrating the state in which thespanner is located to hold the joint in the reference example asillustrated in FIG. 7. FIG. 8 illustrates the above state as viewedside-on with respect to the side surface B of the relay unit 53R. FIG. 9illustrates the above state as viewed side-on view with respect to aside surface that is opposite to the side surface A of the relay unit53R. As illustrated in FIG. 9, in the connection work, the first portion155R of the liquid-pipe joint 151 aR is held and fixed by a spanner1000. In FIGS. 8 and 9, arrows P each indicating a direction in which aforce is applied to the liquid-pipe joint 151 aR by the spanner 1000.

FIG. 8 illustrates a state in which the spanner 1000 is located to holdthe first portion 155R of the liquid-pipe joint 151 aR at aninappropriate angle and is slipped. Referring to FIG. 8, the spanner1000 holds two opposite outer corners of the first portion 155R, not twoopposite outer side surfaces of the first portion 155R. When theliquid-pipe flare nut 152 aR is tightened while the spanner 1000 is keptlocated on the first portion 155R of the liquid-pipe joint 151 aR at aninappropriate angle, an excessive force may be applied to the firstportion 155R of the liquid-pipe joint 151 aR, thus deforming the firstportion 155R and the first pipe 161 aR. Consequently, a crack may beformed at the brazed portion 154R, causing a leak of the refrigerant.

In contrast, the above problem does not occur in the relay unit 53according to Embodiment 1. FIG. 3 is a partial side view illustrating aconfiguration of each of the refrigerant supply pipes in the relay unit53 of Embodiment 1. FIG. 3 illustrates the refrigerant supply pipes asviewed side-on with respect to the side surface A of the relay unit 53.As illustrated in FIG. 3, the liquid-refrigerant supply pipe 143 and thegas-refrigerant supply pipe 144 protrude from the side surface B in thedirection perpendicular to the side surface B of the relay unit 53. Theliquid-refrigerant supply pipe 143 is provided above the gas-refrigerantsupply pipe 144. The length L1 of a protruding portion of theliquid-refrigerant supply pipe 143 is greater than the length L2 of thatof the gas-refrigerant supply pipe 144. In an example as illustrated inFIG. 3, the length L1 of the protruding portion of theliquid-refrigerant supply pipe 143 is 120 mm. However, the length L1 isnot limited to 120 mm. The length L1 may be appropriately set to fallwithin the range of, for example, 100 to 150 mm.

The liquid-refrigerant supply pipe 143 includes a first pipe 161 a fixedto the side surface B of the relay unit 53 and a liquid-pipe joint 151 alocated at a distal end of the first pipe 161 a. The liquid-pipe joint151 a is a first joint. The liquid-pipe joint 151 a is connected to thesecond liquid pipe 105 using a liquid-pipe flare nut 152 a. Thegas-refrigerant supply pipe 144 includes a second pipe 161 b fixed tothe side surface B of the relay unit 53 and a gas-pipe joint 151 blocated at a distal end of the second pipe 161 b. The gas-pipe joint 151b is a second joint. The gas-pipe joint 151 b is connected to the secondgas pipe 106 using a gas-pipe flare nut 152 b.

The configuration of the liquid-pipe joint 151 a in Embodiment 1 isbasically the same as that in the reference example as illustrated inFIG. 7. That is, the liquid-pipe joint 151 a of Embodiment 1 includes afirst portion 155 that is a hexagonal pipe and a second portion 156 tobe fitted in the liquid-pipe flare nut 152 a. The first portion 155 andthe second portion 156 are molded and formed integral with each other.Alternatively, the first portion 155 and the second portion 156 may beformed as separate portions, and then joined to each other. Since thesecond portion 156 is not illustrated in FIG. 3, the second portion 156Ras illustrated in FIG. 7 or the second portion 156 as illustrated inFIG. 4, which will be described later, should be referred to. Since thefirst portion 155 is the hexagonal pipe, the first portion 155 has sixouter side surfaces and six outer corners. The first portion 155 has ahexagonal outer peripheral portion and a circular inner peripheralportion. Furthermore, an end of the first portion 155 in the axialdirection is brazed and fixed to the first pipe 161 a of theliquid-refrigerant supply pipe 143. This brazed portion will hereinafterbe referred to as “brazed portion 154”. Since the brazed portion 154 isnot illustrated in FIG. 3, the brazed portion 154R as illustrated inFIG. 7 or the brazed portion 154 as illustrated in FIG. 4, which will bedescribed later, should be referred to. The second portion 156 isprovided at one of ends of the first portion 155 that is closer to theindoor unit 52 a. The second portion 156 is connected to the indoor heatexchanger 5 a of the indoor unit 52 a by the second liquid pipe 105 aand the indoor expansion device 6 a. The second portion 156 is formed inthe shape of a circular tube. A distal end portion of the second portion156 is tapered toward a distal end of the distal end portion. Since theliquid-pipe flare nut 152 a is screwed onto the second portion 156, anouter peripheral surface of the second portion 156 and an innerperipheral surface of the liquid-pipe flare nut 152 a are processed tohave threads as necessary. The outside diameter of the first portion 155is larger than that of the second portion 156.

As is clear from the comparison between FIGS. 3 and 6, the length L1 ofthe protruding portion of the liquid-refrigerant supply pipe 143 thatprotrudes from the side surface B in Embodiment 1 is greater than thatof the protruding portion of the liquid-refrigerant supply pipe 143R ofthe reference example as illustrated in FIG. 6. In Embodiment 1, thelength L1 of the liquid-refrigerant supply pipe 143 is, for example,double the length L1 of the liquid-refrigerant supply pipe 143R asillustrated in FIG. 6. The length L2 of the gas-refrigerant supply pipe144 in Embodiment 1 is equal to the length L2 of the gas-refrigerantsupply pipe 144R as illustrated in FIG. 6. Therefore, in Embodiment 1,as illustrated in FIG. 3, the length L1 of the liquid-refrigerant supplypipe 143 is greater than the length L2 of the gas-refrigerant supplypipe 144.

Because of provision of the above configuration, in Embodiment 1, thespanner 1000 is easily engaged with the first portion 155 of theliquid-pipe joint 151 a from below the relay unit 53, and theliquid-pipe flare nut 152 a is easily tightened. That is, when thespanner 1000 is moved and engaged with the first portion 155 of theliquid-pipe joint 151 a from below the relay unit 53, thegas-refrigerant supply pipe 144 does not interfere with movement of thespanner 1000. The spanner 1000 can thus be engaged at an appropriateangle with the first portion 155 of the liquid-pipe joint 151 a. It istherefore possible to prevent deformation of the first portion 155 ofthe liquid-pipe joint 151 a and deformation of the liquid-refrigerantsupply pipe 143. Also, it is therefore possible to prevent formation ofa crack at the brazed portion 154 between the liquid-pipe joint 151 aand the first pipe 161 a of the liquid-refrigerant supply pipe 143, thusreducing the likelihood of occurrence of a leak of the refrigerant.

A method of setting the length L1 of the liquid-refrigerant supply pipe143 as illustrated in FIG. 3 will be described. It should be noted thatof the two ends of the first portion 155 of the liquid-pipe joint 151 ain the axial direction, an end closer to the relay unit 53 will bereferred to as “relay-unit-53-side end” and the other end will bereferred to as “indoor-unit-52-side end”. The length L1 may be set suchthat the distance from the side surface B to the indoor-unit-side end ofthe first portion 155 of the liquid-pipe joint 151 a is longer than thedistance from the side surface B to the distal end of thegas-refrigerant supply pipe 144. To be more specific, as illustrated inFIG. 3, the difference between the distance from the side surface B tothe indoor-unit-52-side end of the first portion 155 of the liquid-pipejoint 151 a and the distance from the side surface B to the distal endof the gas-refrigerant supply pipe 144 is a distance D. FIG. 3illustrates a state in which the gas-pipe flare nut 152 b is fitted tothe distal end of the gas-refrigerant supply pipe 144. Thus, strictlyspeaking, the position of the distal end of the gas-refrigerant supplypipe 144 is the position of one of ends of the gas-pipe flare nut 152 bthat is closer to the indoor unit 52. The distance D and the length L1are set such that the distance D is longer than or equal to apredetermined first threshold Dth. As illustrated in FIG. 9, assumingthat the spanner 1000 has a thickness T, the first threshold Dth isdetermined based on the thickness T of the spanner 1000. Specifically,it is preferable that the first threshold Dth be set to the value of thethickness T of the spanner 1000. For example, where the length S of thefirst portion 155 of the liquid-pipe joint 151 a in the axial directionis 17 mm, the thickness T of a round spanner that is compliant withJapanese Industrial Standards (JIS) B 4630 is 8 mm. Thus, it sufficesthat the first threshold Dth is set to 8 mm, and the length L1 is setsuch that the distance D is longer than or equal to the first thresholdDth. When the length S of the first portion 155 of the liquid-pipe joint151 a is changed, the spanner 1000 to be used is also changed. Thus,needless to say, the thickness T of the spanner is changed. In this casealso, it suffices that the first threshold Dth is appropriately setbased on the thickness T of the changed spanner 1000, and the length L1is set such that the distance D is longer than or equal to the firstthreshold Dth. Although in the above description, the spanner is used inthe example described above, it is not limiting, and another tool may beused. If another tool is used, it suffice that the first threshold Dthis appropriately set based on the thickness T of the tool.

As illustrated in FIG. 2, in Embodiment 1, the liquid-refrigerant supplypipes 143 are arranged at regular intervals at the side surface B of therelay unit 53. When the spanner 1000 is used for a singleliquid-refrigerant supply pipe 143, it is preferable that the spanner1000 could be rotated without contacting another liquid-refrigerantsupply pipe 143. It is therefore also preferable that any adjacent twoof the liquid-refrigerant supply pipes 143 be arranged apart from eachother by a distance longer than or equal to a predetermined secondthreshold Wth. As illustrated in FIG. 8, the spanner 1000 has a width WThe second threshold Wth is determined based on the width W of thespanner 1000. Specifically, it is preferable that the second thresholdWth be set to ½ of the width W of the spanner 1000. In such a manner, inthe case where the distance between the adjacent liquid-refrigerantsupply pipes 143 is set longer than or equal to the second thresholdWth, the spanner 1000 can be rotated without contacting anotherliquid-refrigerant supply pipe 143. The same is true of thegas-refrigerant supply pipes 144. In other words, it is preferable thatthat any adjacent two of the gas-refrigerant supply pipes 144 bearranged apart from each other by a distance longer than or equal to thesecond threshold Wt. Although it is described above that theliquid-refrigerant supply pipes 143 are arranged at regular intervals,and the same is true of the gas-refrigerant supply pipes 144, it is notlimiting. That is, it is not indispensable that the liquid-refrigerantsupply pipes 143 are arranged at irregular intervals, and thegas-refrigerant supply pipes 144 are arranged at irregular intervals.Although the tool for use in the above example is the spanner, the toolis not limited to the spanner. Any other tool may be used. Regarding thesecond threshold Wth, if another tool is used, it suffices that thesecond threshold Wth is appropriately set based on the width W of thetool.

FIG. 4 is a partial side view of a configuration of another example ofthe refrigerant supply pipe of the relay unit 53 in Embodiment 1. FIG. 4illustrates a liquid-pipe joint 151 a of the refrigerant supply pipe ina modification of Embodiment 1. In the modification as illustrated inFIG. 4, the liquid-pipe joint 151 a includes the first portion 155 thatis a hexagonal pipe, the second portion 156 to be fitted in theliquid-pipe flare nut 152 a, and a third portion 153 brazed to the firstpipe 161 a of the liquid-refrigerant supply pipe 143. Hereinafter, aportion that is brazed to the third portion 153 and the first pipe 161 aof the liquid-refrigerant supply pipe 143 will be referred to as “brazedportion 154”. The third portion 153 is located at one of ends of thefirst portion 155 that is closer to the relay unit 53. The secondportion 156 is located at the other end of the first portion 155, thatis, one of the ends of the first portion 155 that is closer to theindoor unit 52. The third portion 153 is formed in the shape of acircular tube. Thus, an outer circumferential portion and an innercircumferential portion of the third portion 153 are both circular. Theshapes of the first portion 155 and the second portion 156 of theliquid-pipe joint 151 a are basically the same as those of the firstportion 155 and the second portion 156 of the liquid-pipe joint 151 a inEmbodiment 1. It should be noted that the outside diameter of the thirdportion 153 is smaller than that of the first portion 155. The outsidediameter of the second portion 156 is smaller than that of the firstportion 155. The outside diameter of the second portion 156 may be thesame as or different from that of the third portion 153. As describedabove, the liquid-pipe joint 151 a in the modification as illustrated inFIG. 4 includes the first portion 155, the second portion 156, and thethird portion 153 that is formed in the shape of a circular tube.

As described above, in the modification as illustrated in FIG. 4, thethird portion 153, which is brazed and fixed to the first pipe 161 a ofthe liquid-refrigerant supply pipe 143 by the brazed portion 154, isformed in the shape of a circular tube, not a hexagonal tube. InEmbodiment 1 as described above, the length S of the first portion 155of the liquid-pipe joint 151 a in the axial direction is 17 mm. In themodification as illustrated in FIG. 4, the length of the third portion153 of the liquid-pipe joint 151 a in the axial direction is 5 mm, andthe length S of the first portion of the liquid-pipe joint 151 a in theaxial direction is 12 mm. Therefore, the sum of the length of the firstportion 155 and the length of the third portion 153 in the modificationis 5+12=17 mm, and is the same as the length of the first portion 155 inEmbodiment 1. These widths are merely descried as examples and are notlimiting. The sum of the length of the first portion 155 and the lengthof the third portion 153 in the modification is the same as the lengthof the first portion 155 in Embodiment 1. The sum of the length of thefirst portion 155 and the length of the third portion 153 may be thesame as or different from the length of the first portion 155 inEmbodiment 1.

Advantages of the modification as illustrated in FIG. 4 will bedescribed with reference to FIGS. 5 and 9. FIG. 5 is a diagramillustrating the spanner located to hold the joint included in therefrigerant supply pipe as illustrated in FIG. 4. FIG. 5 illustrates theliquid-pipe joint 151 a in the modification as illustrated in FIG. 4.FIG. 9 is a diagram illustrating the spanner located to hold the jointin the reference example as illustrated in FIG. 7. FIG. 9 illustratesthe liquid-pipe joint 151 aR in the reference example.

FIG. 9 illustrates the spanner 1000 located to hold the liquid-pipejoint 151 aR in the reference example. FIG. 9 is a side view except fora hatched area, which is illustrated as a section. As illustrated inFIG. 9, in this example, the spanner 1000 is located close to the brazedportion 154R. Thus, if the first portion 155R of the liquid-pipe joint151 aR is deformed, this deformation easily affects the brazed portion154R, and a crack may be formed in the brazed portion 154R. Furthermore,as is clear from the hatched area as illustrated as the section in FIG.9, the spanner 1000 is located only on thin part of the first portion155R of the liquid-pipe joint 151 aR, as a result of which the firstportion 155R may be easily deformed.

FIG. 5 illustrates the spanner 1000 located to hold the liquid-pipejoint 151 a in the modification of Embodiment 1, which is illustrated inFIG. 4. FIG. 5 is a side view except for a hatched area, which isillustrated as a section. In FIG. 5, arrows P each indicate a directionin which a force is applied to the liquid-pipe joint 151 a by thespanner 1000. As illustrated in FIG. 5, the liquid-pipe joint 151 a inthe modification includes the third portion 153 formed in the shape of acircular tube, as described with reference to FIG. 4. In this case, thespanner 1000 is located on the first portion 155 of the liquid-pipejoint 151 a, but not on the third portion 153. Therefore, the distancebetween the brazed portion 154 and the spanner 1000 is longer than thatin the reference example as illustrated in FIG. 9. Thus, even if thefirst portion 155 of the liquid-pipe joint 151 a is deformed, thisdeformation does not affect the brazed portion 154. As is clear from thehatched area as illustrated as the section in FIG. 5, the spanner 1000is located on thick part of the first portion 155 of the liquid-pipejoint 151 a. Accordingly, the first portion 155 is not easily deformed.Thus, it is possible to prevent formation of crack in the brazed portion154, thus preventing occurrence of a leak of the refrigerant.

Although the liquid-pipe joint 151 a is described above with referenceto FIGS. 4 and 5, the gas-pipe joint 151 b may be also formed to have athird portion 153 formed in the shape of a circular tube. The followingis a description concerning the case where the gas-pipe joint 151 b isformed to have a third portion 153 formed in the shape of a circulartube. Since the configuration of the gas-pipe joint 151 b is basicallythe same as that of the liquid-pipe joint 151 a, the gas-pipe joint 151b formed in the above manner will also be described with reference toFIGS. 4 and 5. In this description, reference signs 151 a and 161 aindicated in FIGS. 4 and 5 are replaced by reference signs 151 b and 161b. The gas-pipe joint 151 b includes a first portion 155, a secondportion 156, and a third portion 153. The first portion 155 of thegas-pipe joint 151 b is provided at the distal end of the second pipe161 b. The second portion 156 of the gas-pipe joint 151 b is provided atone of ends of the first portion 155 of the gas-pipe joint 151 b that iscloser to the indoor unit 52 b, and is connected to the indoor heatexchanger 5 b of the indoor unit 52 b via the second liquid pipe 105 band the indoor expansion device 6 b. The third portion 153 of thegas-pipe joint 151 b is provided at an end portion of the first portion155 of the gas-pipe joint 151 b that is closer to the relay unit 53, andis brazed to the second pipe 161 b of the gas-refrigerant supply pipe144 by the brazed portion 154. Therefore, needless to say, in the casewhere the gas-pipe joint 151 b includes the third portion 153, it ispossible to obtain the same advantages as in the case where theliquid-pipe joint 151 a includes the third portion 153.

As described above, the relay unit 53 of Embodiment 1 includes theliquid-refrigerant supply pipe 143, which is the first refrigerantsupply pipe, and the gas-refrigerant supply pipe 144, which is thesecond refrigerant supply pipe. The liquid-refrigerant supply pipe 143and the gas-refrigerant supply pipe 144 protrude from the side surface Bof the relay unit 53, that is, from the same side surface. Theliquid-refrigerant supply pipe 143 is provided above the gas-refrigerantsupply pipe 144. The length L1 of the protruding portion of theliquid-refrigerant supply pipe 143 that protrudes from the side surfaceB is set longer than the length L2 of the protruding portion of thegas-refrigerant supply pipe 144 that protrudes from the side surface B.Thus, the gas-refrigerant supply pipe 144 does not interfere with theconnection work of connecting the liquid-refrigerant supply pipe 143,and the spanner 1000 can be moved and engaged with to the liquid-pipejoint 151 a at an appropriate angle and the liquid-pipe flare nut 152 acan thus be tightened by the spanner 1000. Therefore, the spanner 1000is not engaged with the liquid-pipe joint 151 a at an inappropriateangle. It is therefore possible to prevent deformation of theliquid-pipe joint 151 a, thereby preventing damage to the brazed portion154 and also occurrence of a refrigerant leak.

Regarding Embodiment 1, although it is described above that the firstrefrigerant supply pipe is the liquid-refrigerant supply pipe 143, andthe second refrigerant supply pipe is the gas-refrigerant supply pipe144, it is not limiting, and the relationship between these componentsmay be reversed. That is, the first refrigerant supply pipe may be thegas-refrigerant supply pipe 144, and the second refrigerant supply pipemay be the liquid-refrigerant supply pipe 143. In either case, in thecase where the first refrigerant supply pipe is provided above thesecond refrigerant supply pipe, the length L1 of the first refrigerantsupply pipe is set longer than the length L2 of the second refrigerantsupply pipe. As a result, the workability at the time of connecting thefirst refrigerant supply pipe can be improved.

In the modification of Embodiment 1 as illustrated in FIGS. 4 and 5, theliquid-refrigerant supply pipe 143 includes the first pipe 161 a and theliquid-pipe joint 151 a, which is a first joint. The liquid-pipe joint151 a includes the first portion 155, the second portion 156, and thethird portion 153. The first portion 155 of the first joint is providedat the distal end of the first pipe 161 a. The second portion 156 isprovided at one of the ends of the first portion 155 that is closer tothe indoor unit 52 a, and is connected to the indoor heat exchanger 5 aof the indoor unit 52 a. The third portion 153 is provided at one of theends of the first portion 155 that is closer to the relay unit 53, andis fixed to the first pipe 161 a by the brazed portion 154. The firstportion 155, the second portion 156, and the third portion 153 aremolded and formed integrally with each other. Alternatively, at leastone of the first portion 155, the second portion 156, and the thirdportion 153 may be formed independently of the others, and then jointedto the others. Since the spanner 1000 is located on the first portion155, the spanner 1000 is not located on the third portion 153. Since thethird portion 153 is located between the first portion 155 and thebrazed portion 154, in the connection work, the spanner 1000 is locatedapart from the brazed portion 154 by a longer distance. Thus, even ifthe first portion 155 of the liquid-pipe joint 151 a is deformed, thisdeformation does not easily affect the brazed portion 154. It istherefore possible to prevent formation of a crack in the brazed portion154, thus preventing occurrence of a leak of the refrigerant.

Similarly, the gas-pipe joint 151 b, which is the second joint, may beformed to have the first portion 155, the second portion 156, and thethird portion 153. In this case, the third portion 153 is fixed to thesecond pipe 161 b by the brazed portion 154. Therefore, since the thirdportion 153 is located between the first portion 155 and the brazedportion 154, in the connection work, the spanner 1000 is located apartfrom the brazed portion 154 by a longer distance. Thus, even if thefirst portion 155 of the gas-pipe joint 151 b is deformed, thisdeformation does not easily affect the brazed portion 154. Therefore, itis possible to prevent formation of a crack in the brazed portion 154,thus preventing occurrence of a leak of the refrigerant.

1. An air-conditioning apparatus comprising: an outdoor unit includingan outdoor heat exchanger; an indoor unit including an indoor heatexchanger; and a relay unit provided between the outdoor unit and theindoor unit, and including one or more first refrigerant supply pipesand one or more second refrigerant supply pipes that are connected tothe indoor heat exchanger of the indoor unit, wherein the one or morefirst refrigerant supply pipes and the one or more second refrigerantsupply pipes protrude from a side surface of the relay unit, the one ormore first refrigerant supply pipes are each provided above anassociated one of the one or more second refrigerant supply pipes, alength of part of the one or more first refrigerant supply pipes thatprotrudes from the side surface is greater than a length of part of theone or more second refrigerant supply pipes that protrudes from the sidesurface, the one or more first refrigerant supply pipes each include: afirst pipe fixed to the side surface of the relay unit and a first jointlocated at a distal end of the first pipe, the first joint has: a firstportion located at the distal end of the first pipe; a second portionthat is located at one of ends of the first portion that is closer tothe indoor unit, the second portion being connected to the indoor heatexchanger of the indoor unit a third portion that is formed in the shapeof a circular tube and located at the other end of the first portion,the other end of the first portion being closer to the relay unit and abrazed portion located between the third portion and the first pipe ofthe first refrigerant supply pipe, and brazing the third portion to thefirst pipe of the first refrigerant supply pipe, and a distance from theside surface to the one of the ends of the first portion is longer thana distance from the side surface to a distal end of the secondrefrigerant supply pipe. 2-3. (canceled)
 4. The air-conditioningapparatus of claim 1, wherein the number of the one or more firstrefrigerant supply pipes is two or more, and the number of the one ormore second refrigerant supply pipes is two or more, any adjacent two ofthe one or more first refrigerant supply pipes are provided apart fromeach other, and any adjacent two of the one or more second refrigerantsupply pipes are provided apart from each other.
 5. The air-conditioningapparatus of claim 1, wherein the one or more second refrigerant supplypipes each include: a second pipe fixed to the side surface of the relayunit; and a second joint located at a distal end of the second pipe, thesecond joint includes a first portion, a second portion, a thirdportion, and a brazed portion, the first portion of the second joint islocated at the distal end of the second pipe, the second portion of thesecond joint is located at one of ends of the first portion of thesecond joint that is closer to the indoor unit, and is connected to theindoor heat exchanger of the indoor unit, and the third portion of thesecond joint is formed in the shape of a circular tube, located at theother end of the first portion of the second joint, and fixed to thesecond pipe of an associated one of the one or more second refrigerantsupply pipes by the brazed portion of the second joint, the other end ofthe first portion being closer to the relay unit.
 6. Theair-conditioning apparatus of claim 1, wherein the one or more firstrefrigerant supply pipes are each a liquid refrigerant supply pipethrough which liquid refrigerant flows, and the one or more secondrefrigerant supply pipes are each a gas refrigerant supply pipe throughwhich gas refrigerant flows.